how to remove background from any image in android - android

I want to remove the background of photo .but not able to find anything relevant actually I want this type of application https://play.google.com/store/apps/details?id=com.outthinking.bgeraser
of feature in android java code remove the background.
My code is :
public class FingerText extends Activity
{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
//this is the line that sets the initial pen color
mPaint.setColor(inkColor);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(2);
}
private Paint mPaint;
private Bitmap mBitmap;
private boolean inkChosen;
private int bgColor = 0x00000000; //set initial bg color var to white
private int inkColor = 0xFF000000; //set initial ink color var to black
public void colorChanged(int color) {
//This is the implementation of the interface from colorpickerdialog.java
if (inkChosen) {
mPaint.setColor(color);
inkColor = color;
} else {
mBitmap.eraseColor(color);
bgColor = color;
//set the color to the user's last ink color choice
mPaint.setColor(inkColor);
}
}
public class MyView extends View {
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
public MyView(Context c) {
super(c);
mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
//this sets the bg color for the bitmap
mBitmap.eraseColor(bgColor);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
//this is the line that changes the bg color in the initial canvas
canvas.drawColor(bgColor);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
canvas.drawBitmap(((BitmapDrawable)getResources().getDrawable(
R.drawable.ic_alphabets)).getBitmap(),0, 0, mBitmapPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
private static final int BG_COLOR_ID = Menu.FIRST;
private static final int INK_MENU_ID = Menu.FIRST + 1;
private static final int CLEAR_MENU_ID = Menu.FIRST + 2;
private static final int ERASER_MENU_ID = Menu.FIRST + 3;
private static final int SEND_MENU_ID = Menu.FIRST + 4;
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, BG_COLOR_ID, 0, "Background Color").setShortcut('3', 'b');
menu.add(0, INK_MENU_ID, 0, "Ink Color").setShortcut('4', 'c');
menu.add(0, CLEAR_MENU_ID, 0, "Clear All").setShortcut('5', 'e');
menu.add(0, ERASER_MENU_ID, 0, "Eraser").setShortcut('6', 'x');
menu.add(0, SEND_MENU_ID, 0, "Send").setShortcut('7', 's');
return true;
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
switch (item.getItemId()) {
case BG_COLOR_ID:
inkChosen = false;
return true;
case INK_MENU_ID:
inkColor = mPaint.getColor();
inkChosen = true;
return true;
case CLEAR_MENU_ID:
mBitmap.eraseColor(bgColor);
return true;
case ERASER_MENU_ID:
//set pen color to bg color for 'erasing'
mPaint.setColor(bgColor);
return true;
case SEND_MENU_ID:
FileInputStream ifs;
try {
FileOutputStream fs = openFileOutput("message_image", Context.MODE_PRIVATE);
mBitmap.compress(Bitmap.CompressFormat.PNG, 100, fs);
ifs = openFileInput("message_image");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return true;
}
// inserts file pointed to by ifs into image gallery
String url = MediaStore.Images.Media.insertImage(getContentResolver(),
BitmapFactory.decodeStream(ifs),
"Message image1", "Message image");
Intent sendIntent = new Intent(Intent.ACTION_SEND);
sendIntent.putExtra("sms_body", "Message created using FingerText");
sendIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse(url));
sendIntent.setType("image/png");
startActivity(sendIntent);
bgColor = 0xFFFFFFFF; //set bg color var back to white
inkColor = 0xFF000000; //set ink color var back to black
mBitmap.eraseColor(bgColor);
return true;
}
return super.onOptionsItemSelected(item);
}
}
Please Help Me Thanks in advance.

i am done it here is my code use as it is:
public class DrawView extends View implements View.OnTouchListener {
private ArrayList<PathPoints> paths = new ArrayList<PathPoints>();
private ArrayList<PathPoints> undonePaths = new ArrayList<PathPoints>();
private Path mPath;
private int x = 0;
private int y = 0;
Bitmap bitmap;
Bitmap bitmap2;
Canvas bitmapCanvas;
Drawable d;
private final Paint paint = new Paint();
private final Paint eraserPaint = new Paint();
Matrix matrix;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;
int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public DrawView(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
// Set background
this.setBackgroundResource(R.drawable.transparentbg);
// Set bitmap
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.shert).copy(Bitmap.Config.ARGB_8888, true);
bitmap = Bitmap.createScaledBitmap(bitmap, 600, 900, true);
bitmapCanvas = new Canvas();
bitmapCanvas.setBitmap(bitmap);//Bitmap.createScaledBitmap(bitmap, 350,400, true)
bitmapCanvas.drawColor(Color.TRANSPARENT);
// Set eraser paint properties
eraserPaint.setColor(Color.TRANSPARENT);
eraserPaint.setAlpha(0);
eraserPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
eraserPaint.setAntiAlias(true);
mPath = new Path();
paths.add(new PathPoints(mPath, Color.TRANSPARENT, false));
}
#Override
public void onDraw(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT);
bitmapCanvas.drawColor(Color.TRANSPARENT);
bitmapCanvas.drawCircle(x, y, 20, eraserPaint);
canvas.drawBitmap(bitmap, 0, 0, paint);
}
public boolean onTouch(View view, MotionEvent event) {
x = (int) event.getX();
y = (int) event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 0;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
bitmapCanvas.drawPath(mPath, eraserPaint);
// kill this so we don't double draw
mPath = new Path();
paths.add(new PathPoints(mPath, Color.TRANSPARENT, false));
}
public static Bitmap scaleDown(Bitmap realImage, float maxImageSize,
boolean filter) {
float ratio = Math.min(
(float) maxImageSize / realImage.getWidth(),
(float) maxImageSize / realImage.getHeight());
int width = Math.round((float) ratio * realImage.getWidth());
int height = Math.round((float) ratio * realImage.getHeight());
Bitmap newBitmap = Bitmap.createScaledBitmap(realImage, width,
height, filter);
return newBitmap;
}
void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
float fixTransY = getFixTrans(transY, viewHeight, origHeight
* saveScale);
if (fixTransX != 0 || fixTransY != 0)
matrix.postTranslate(fixTransX, fixTransY);
}
float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
public void onClickUndo() {
if (paths.size() > 0) {
undonePaths.add(paths.remove(paths.size() - 1));
invalidate();
} else {
}
// toast the user
}
public void onClickRedo() {
if (undonePaths.size() > 0) {
paths.add(undonePaths.remove(undonePaths.size() - 1));
invalidate();
} else {
}
// toast the user
}
class PathPoints {
private Path path;
// private Paint eraserPaint;
private int color;
private String textToDraw;
private boolean isTextToDraw;
private int x, y;
public PathPoints(Path path, int color, boolean isTextToDraw) {
this.path = path;
this.color = color;
this.isTextToDraw = isTextToDraw;
}
public PathPoints(int color, String textToDraw, boolean isTextToDraw,
int x, int y) {
this.color = color;
this.textToDraw = textToDraw;
this.isTextToDraw = isTextToDraw;
this.x = x;
this.y = y;
}
public Path getPath() {
return path;
}
public void setPath(Path path) {
this.path = path;
}
public int getColor() {
return color;
}
public void setColor(int color) {
this.color = color;
}
public String getTextToDraw() {
return textToDraw;
}
public void setTextToDraw(String textToDraw) {
this.textToDraw = textToDraw;
}
public boolean isTextToDraw() {
return isTextToDraw;
}
public void setTextToDraw(boolean isTextToDraw) {
this.isTextToDraw = isTextToDraw;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
}
}
This code is working in my live project thanks.

Related

canvas.drawPath() is not drawing in real-time

As building upon this drawing library here, the library didn't provide a way to change stroke color or width of a single one but only changing those properties of all of the drawen strokes at the same time. So I decided to seperate each stroke with its own property to be drawen. However now the drawing stroke is not appearing in real-time when moving the finger on the screen. The whole stroke only appears upon the touch_up() function. I assume the problem is from canvas.drawPath(myPath, myPaint); in the onDraw() function but I can not manage to find what causes the problem. Does anyone know what the problem of the strokes not drawing in real-time is? Or how to fix it?
DrawingView.java:
public class DrawingView extends View {
private Paint canvasPaint;
private Canvas drawCanvas;
private Bitmap canvasBitmap;
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private ArrayList<float[]> PointsCal = new ArrayList<float[]>();
private ArrayList<float[]> Points = new ArrayList<float[]>();
private ArrayList<Integer> id = new ArrayList<Integer>();
private int counter;
public static WebSocket ws;
private OkHttpClient client;
Context myContext;
Stroke drawnStroke;
private List<Stroke> allStrokes;
public DrawingView(Context context, AttributeSet attr) {
super(context, attr);
setupDrawing();
myContext = context;
}
private void setupDrawing() {
allStrokes = new ArrayList<Stroke>();
drawnStroke = new Stroke();
canvasPaint = new Paint(Paint.DITHER_FLAG);
drawCanvas = new Canvas();
drawnStroke.paint.setAntiAlias(true);
drawnStroke.paint.setStyle(Paint.Style.STROKE);
drawnStroke.paint.setStrokeJoin(Paint.Join.ROUND);
drawnStroke.paint.setStrokeCap(Paint.Cap.ROUND);
counter = 0;
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
drawCanvas = new Canvas(canvasBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
if (allStrokes != null) {
for (Stroke stroke : allStrokes) {
if (stroke != null) {
Path myPath = stroke.getPath();
Paint myPaint = stroke.getPaint();
myPaint.setAntiAlias(true);
myPaint.setStyle(Paint.Style.STROKE);
//this function below is not rendering in real time
canvas.drawPath(myPath, myPaint);
}
}
}
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
drawnStroke.getPaint().setColor(UserSettings.color);
drawnStroke.getPaint().setStrokeWidth(UserSettings.width);
drawnStroke.getPath().moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
drawnStroke.path.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
drawnStroke.path.lineTo(mX, mY);
drawCanvas.drawPath(drawnStroke.path, drawnStroke.paint);
allStrokes.add(drawnStroke);
drawnStroke = new Stroke();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
float coordinates[] = {0f, 0f};
float coord[] = {0f, 0f};
String eventString;
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
coordinates[0] = x;
coordinates[1] = y;
PointsCal.add(coordinates);
Points.add(coordinates);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
coordinates[0] = x;
coordinates[1] = y;
PointsCal.add(coordinates);
coord[0] = coordinates[0] - PointsCal.get(PointsCal.size() - 2)[0];
coord[1] = coordinates[1] - PointsCal.get(PointsCal.size() - 2)[1];
Points.add(coord);
break;
case MotionEvent.ACTION_UP:
touch_up();
coordinates[0] = x;
coordinates[1] = y;
PointsCal.add(coordinates);
coord[0] = coordinates[0] - PointsCal.get(PointsCal.size() - 2)[0];
coord[1] = coordinates[1] - PointsCal.get(PointsCal.size() - 2)[1];
Points.add(coord);
String sample = "";
if (Points.size() > 2) {
counter++;
id.add(counter);
sample += ("#" + counter);
for (int i = 0; i < Points.size(); i++) {
sample += ("#" + Arrays.toString(Points.get(i)));
}
} else {
paths.remove(paths.size() - 1);
}
Points.clear();
PointsCal.clear();
invalidate();
break;
}
return true;
}
I believe this is because allStrokes.add(drawnStroke); is not called until the private method touch_up is called, so when iterating over allStrokes for drawing purposes, the current stroke is omitted. Try moving that line of code to touch_start.

How to plot dots on the pattern in a uniform distance in a canvas

What i have: Using the below code i am able to draw a pattern(Ex: Line) in the canvas.
What i am planning to do Or How to do this: I am trying to plot dots on that pattern in a uniform distance. (Hope i am clear)
ActDrawPaintImage.java
public class ActDrawPaintImage extends AppCompatActivity implements ColorPickerDialog.OnColorChangedListener {
MyView mv;
AlertDialog dialog;
#Bind(R.id.toolbar)
Toolbar mToolbar;
#Bind(R.id.btnNxtId)
Button btnNxtId;
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
LinearLayout canvasLayoutId;
boolean mDotToDraw=false;
private int BRUSHSIZE=20;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_draw_paint_image);
//Bind the views
ButterKnife.bind(this);
initToolbar();
onClickSet();
//ADD THE VIEW WHERE THE IMAGE IS DRAWN
setTheCanvasView();
//SET BRUSH PROPERTIES
setUpBrushProperties();
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
private void onClickSet() {
btnNxtId.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mDotToDraw==false){
mDotToDraw=true;
}else{
mDotToDraw=false;
}
}
});
}
private void setTheCanvasView() {
mv= new MyView(this);
mv.setDrawingCacheEnabled(true);
canvasLayoutId=(LinearLayout) findViewById(R.id.canvasLayoutId);
canvasLayoutId.addView(mv);
}
private void setUpBrushProperties() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.pattern_color));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(BRUSHSIZE);
}
private void initToolbar() {
setSupportActionBar(mToolbar);
setTitle(getString(R.string.app_name));
mToolbar.setTitleTextColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.white));
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
Context context;
private int width;
private int height;
public MyView(Context c) {
super(c);
context=c;
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width=w;
height=h;
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SCREEN));
//mPaint.setMaskFilter(null);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
//Create a pointer and log the output
Log.d("POINTS", x + "," + y);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if(mDotToDraw==false){
touch_start(x, y);
}else{
touch_draw_circle(x, y);
}
invalidate();
break;
case MotionEvent.ACTION_MOVE:
if(mDotToDraw==false){
touch_move(x, y);
}else{
}
invalidate();
break;
case MotionEvent.ACTION_UP:
if(mDotToDraw==false){
touch_up();
}else{
}
invalidate();
break;
}
return true;
}
private void touch_draw_circle(float x, float y) {
/*int radius;
radius = 30;
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.WHITE);
mCanvas.drawPaint(paint);
// Use Color.parseColor to define HTML colors
paint.setColor(Color.parseColor("#FF0000"));
mCanvas.drawCircle(x / 2, y / 2, radius, paint);*/
// mPath.quadTo(x, y, x + 0.1f, y);
/*Paint mPaint = new Paint();*/
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.white));
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(BRUSHSIZE);
mPath.addCircle(x, y, mPaint.getStrokeWidth()/4f, Path.Direction.CW);
}
public void clear()
{
mBitmap = Bitmap.createBitmap(width,height , Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
invalidate();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
new MenuInflater(this).inflate(R.menu.draw_paint_image, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
switch (item.getItemId()) {
case R.id.COLOR_MENU_ID:
new ColorPickerDialog(this, this, mPaint.getColor()).show();
return true;
case R.id.EMBOSS_MENU_ID:
if (mPaint.getMaskFilter() != mEmboss) {
mPaint.setMaskFilter(mEmboss);
} else {
mPaint.setMaskFilter(null);
}
return true;
case R.id.BLUR_MENU_ID:
if (mPaint.getMaskFilter() != mBlur) {
mPaint.setMaskFilter(mBlur);
} else {
mPaint.setMaskFilter(null);
}
return true;
case R.id.ERASE_MENU_ID:
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
mPaint.setAlpha(0x80);
return true;
case R.id.Clear:
mv.clear();
return true;
case R.id.Save:
AlertDialog.Builder editalert = new AlertDialog.Builder(ActDrawPaintImage.this);
editalert.setTitle("Please Enter the name with which you want to Save");
final EditText input = new EditText(ActDrawPaintImage.this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.FILL_PARENT);
input.setLayoutParams(lp);
editalert.setView(input);
editalert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
String name= input.getText().toString();
Bitmap bitmap = mv.getDrawingCache();
String path = Environment.getExternalStorageDirectory().getAbsolutePath();
File file = new File("/sdcard/"+name+".png");
try
{
if(!file.exists())
{
file.createNewFile();
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 10, ostream);
ostream.close();
mv.invalidate();
}
catch (Exception e)
{
e.printStackTrace();
}finally
{
mv.setDrawingCacheEnabled(false);
}
}
});
editalert.show();
return true;
}
return super.onOptionsItemSelected(item);
}
}
EDIT
public class ActDrawPaintImage extends AppCompatActivity implements ColorPickerDialog.OnColorChangedListener {
MyView mv;
AlertDialog dialog;
#Bind(R.id.toolbar)
Toolbar mToolbar;
#Bind(R.id.btnNxtId)
Button btnNxtId;
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
LinearLayout canvasLayoutId;
boolean mDotToDraw=false;
private int BRUSHSIZE=20;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_draw_paint_image);
//Bind the views
ButterKnife.bind(this);
initToolbar();
onClickSet();
//ADD THE VIEW WHERE THE IMAGE IS DRAWN
setTheCanvasView();
//SET BRUSH PROPERTIES
setUpBrushProperties();
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
private void onClickSet() {
btnNxtId.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mDotToDraw==false){
mDotToDraw=true;
}else{
mDotToDraw=false;
}
}
});
}
private void setTheCanvasView() {
mv= new MyView(this);
mv.setDrawingCacheEnabled(true);
canvasLayoutId=(LinearLayout) findViewById(R.id.canvasLayoutId);
canvasLayoutId.addView(mv);
}
private void setUpBrushProperties() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.pattern_color));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(BRUSHSIZE);
}
private void initToolbar() {
setSupportActionBar(mToolbar);
setTitle(getString(R.string.app_name));
mToolbar.setTitleTextColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.white));
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
Context context;
private int width;
private int height;
PathMeasure pathMeasure;
float[] position = new float[2];
float[] slope = new float[2]; // slope will give you the tangent of the position on the path. Not sure if you need this.
public MyView(Context c) {
super(c);
context=c;
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
pathMeasure = new PathMeasure(mPath, false);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width=w;
height=h;
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
drawPlotPoints(canvas); // you should be able to implement this alone. It should draw a dot at a given x/y.
canvas.drawPath(mPath, mPaint);
}
private void drawPlotPoints(Canvas canvas) {
int amountOfPoints = (int)(pathMeasure.getLength() / 120f);
for (float distance = 0; distance <= 1; distance += 1f / amountOfPoints) {
pathMeasure.getPosTan(distance, position, slope);
touch_draw_circle(position[0], position[1]);
}
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
//drawPlotPoints(x,y);
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SCREEN));
//mPaint.setMaskFilter(null);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
//Create a pointer and log the output
//Log.d("POINTS", x + "," + y);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if(mDotToDraw==false){
touch_start(x, y);
}else{
touch_draw_circle(x, y);
}
invalidate();
break;
case MotionEvent.ACTION_MOVE:
if(mDotToDraw==false){
touch_move(x, y);
}else{
}
invalidate();
break;
case MotionEvent.ACTION_UP:
if(mDotToDraw==false){
touch_up();
}else{
}
invalidate();
break;
}
return true;
}
private void touch_draw_circle(float x, float y) {
/*int radius;
radius = 30;
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.WHITE);
mCanvas.drawPaint(paint);
// Use Color.parseColor to define HTML colors
paint.setColor(Color.parseColor("#FF0000"));
mCanvas.drawCircle(x / 2, y / 2, radius, paint);*/
// mPath.quadTo(x, y, x + 0.1f, y);
/*Paint mPaint = new Paint();*/
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(ContextCompat.getColor(ActDrawPaintImage.this, R.color.white));
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(BRUSHSIZE);
mPath.addCircle(x, y, mPaint.getStrokeWidth()/4f, Path.Direction.CW);
}
public void clear()
{
mBitmap = Bitmap.createBitmap(width,height , Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
invalidate();
}
}
}
I am getting output as below:
I am trying to get output as like this:
If I understood you correctly, you're trying to discover certain positions on a given path, then draw dots on them where the distance between each dot should be the same.
You can achieve this using a PathMeasure object. Example:
boolean forceClose = false; //(set to true if you want to close the path or leave it open).
PathMeasure pathMeasure = new PathMeasure(path, forceClose);
float[] position = new float[2];
float[] slope = new float[2]; // slope will give you the tangent of the position on the path. Not sure if you need this.
for (float distance = 0; distance <= 1; distance += 1f / AMOUNT_OF_POINTS) {
pathMeasure.getPosTan(distance, position, slope);
drawDotAtPosition(position[0], position[1]); // you should be able to implement this alone. It should draw a dot at a given x/y.
}
The getPosTan method will give you the position on a given path after a certain ratio of the length has passed. This ratio is defined by AMOUNT_OF_POINTS which you can set to anything for a constant amount of points no matter what the length of the path is, or you could calculate it according to the length of the path:
// this will produce an amount of points equal to 1 point per 10 pixels along the whole path
int amountOfPoints = (int)(pathMeasure.getLength() / 10f);
Hope this helps.
I made this a while back, its not exactly my best work but it worked at the time. Maybe you can use it as a reference.
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
public class line_graph extends View
{
private int padding = 0;
private int width = 0;//this is automatically
private int height = 0;
private Paint paint = new Paint();
private String[] labels;// labels for each column
private int[][] values;// values for each column
private String[] labelsHeadings;// headings for each segment of data
private float xInterval = 0;//space between x grid lines
private float yInterval = 0;//space between y grid lines
private int RowLineCount = 0; // amount of y grid lines
private float scale = 1; // this is automatically set according to the screen density
private int labelSpaceLeft = 0;// space on the left for labels
private int labelSpaceBottom = 0;// space on the bottom for labels
private int keySpace = 0;// space on the bottom for the key
private Path path = new Path();// bothe these paths are used for the shaded effect on the line graph
private Path path2 = new Path();
public line_graph(Context context)
{
this(context, null, 0);
}
public line_graph(Context context, AttributeSet attrs)
{
this(context, attrs, 0);
}
public line_graph(Context context, AttributeSet attrs, int defStyleAttr)
{
super(context, attrs, defStyleAttr);
if(isInEditMode())
return;
scale = context.getResources().getDisplayMetrics().density;
labelSpaceLeft = (int)(40 * scale);
labelSpaceBottom = (int)(85 * scale);
keySpace = (int)(40 * scale);
}
public void setup(String[] labels, int[][] values, String[] labelsHeadings, int padding)
{
this.labels = labels;
this.values = values;
this.padding = padding;
this.labelsHeadings = labelsHeadings;
invalidate();
}
#Override
protected void onSizeChanged(int xNew, int yNew, int xOld, int yOld){
super.onSizeChanged(xNew, yNew, xOld, yOld);
width = xNew;
height = yNew;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isInEditMode())
return;
try {
paint.reset();
paint.setAntiAlias(true);
paint.setTextSize(16);
paint.setTextAlign(Paint.Align.RIGHT);
int maxValue = 0;
for (int i = 0; i < values.length; i++) {
for (int j = 0; j < values[i].length; j++) {
maxValue = Math.max(maxValue, values[i][j]);
}
}
float innerWidth = width - padding * 2 - labelSpaceLeft;
float innerHeight = height - padding * 2 - labelSpaceBottom - keySpace;
float lx = padding;
paint.setTextAlign(Paint.Align.LEFT);
for (int i = 0; i < values.length; i++) {
paint.setColor(getNextColour(i));
//calculate space for circles
lx += 15 * scale;
//calculate space key label
if (labelsHeadings.length > i) {
lx += padding + paint.measureText(labelsHeadings[i]);
if (i < values.length - 1 && lx + paint.measureText(labelsHeadings[i + 1]) > width) {
lx = padding + labelSpaceLeft;
innerHeight += paint.ascent();
}
}
}
lx = padding + labelSpaceLeft;
float ly = innerHeight + padding*2 + labelSpaceBottom;
paint.setTextAlign(Paint.Align.LEFT);
for (int i = 0; i < values.length; i++) {
paint.setColor(getNextColour(i));
//draw circles
canvas.drawOval(new RectF(lx - 5 * scale, ly - 5 * scale, lx + 5 * scale, ly + 5 * scale), paint);
lx += 15 * scale;
//draw key label
canvas.drawText(labelsHeadings[i], lx, ly - paint.ascent() / 2, paint);
if (labelsHeadings.length > i) {
lx += padding + paint.measureText(labelsHeadings[i]);
if (i < values.length - 1 && lx + paint.measureText(labelsHeadings[i + 1]) > width) {
lx = padding + labelSpaceLeft;
ly -= paint.ascent();
innerHeight += paint.ascent();
}
}
}
xInterval = innerWidth / (labels.length-1);
RowLineCount = (int) Math.min(Math.max(innerHeight / Math.ceil(40 * scale), 2), maxValue/2);
yInterval = innerHeight / RowLineCount;
int currentValue = maxValue;
float y;
paint.setTextAlign(Paint.Align.RIGHT);
for (int i = 0; i < RowLineCount+1; i++) {
//draw left label
y = yInterval * i + padding;
paint.setColor(0xffaaaaaa);
canvas.drawText(String.valueOf(currentValue), labelSpaceLeft, y - paint.ascent()/2, paint);
currentValue = Math.max(currentValue - maxValue/RowLineCount,0);
//draw x grid line
paint.setColor(0xffeeeeee);
canvas.drawLine(padding + labelSpaceLeft, y, innerWidth + padding + labelSpaceLeft, y, paint);
}
float x;
for (int i = 0; i < labels.length; i++) {
//draw bottom label rotated
x = xInterval * i + padding + labelSpaceLeft;
if(i != labels.length) {
canvas.save();
canvas.rotate(300, x, innerHeight + padding*2 - paint.ascent()/2);
paint.setColor(0xffaaaaaa);
canvas.drawText(labels[i], x, innerHeight + padding*2 - paint.ascent()/2, paint);
canvas.restore();
}
//draw y grid line
paint.setColor(0xffeeeeee);
canvas.drawLine(x, padding, x, innerHeight + padding, paint);
}
paint.setStyle(Paint.Style.FILL);
for (int i = 0; i < values.length; i++) {
paint.setColor(getNextColour(i));
path.rewind();
path2.rewind();
for (int j = 0; j < values[i].length; j++)
{
x = xInterval * j + padding + labelSpaceLeft;
y = innerHeight + padding - (innerHeight * values[i][j] / maxValue);
//draw lines
if(j == 0) {
path2.moveTo(padding + labelSpaceLeft, innerHeight + padding);
path.moveTo(x, y);
}
else
path.lineTo(x,y);
path2.lineTo(x, y);
//canvas.drawLine(xOld,yOld,x,y,paint);
//draw circles
canvas.drawOval(new RectF(x - 5 * scale, y - 5 * scale, x + 5 * scale, y + 5 * scale), paint);
}
//draw line
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(2);
canvas.drawPath(path, paint);
//draw shaded area
path2.lineTo(innerWidth + padding + labelSpaceLeft, innerHeight + padding);
paint.setARGB(20, Color.red(paint.getColor()), Color.green(paint.getColor()), Color.blue(paint.getColor()));
paint.setStyle(Paint.Style.FILL);
canvas.drawPath(path2, paint);
}
}
catch (Exception ignored){}
}
//used to get the next color in the series
public static int getNextColour(int index)
{
int[] colours = new int[]{0xFF4CAF50,
0xFF9C27B0,
0xFFF44336,
0xFF00BCD4,
0xFFE91E63,
0xFF03A9F4,
0xFFFF9800,
//0xFFFFEB3B,//removed bright yellow
0xFF9E9E9E,
0xFF795548,
0xFF8BC34A,
0xFF607D8B,
0xFF009688,
0xFFFFC107,
0xFF673AB7,
0xFF2196F3,
0xFFCDDC39,
0xFF3F51B5,
0xFFFF5722};
return colours[index % colours.length];
}
}
its used like this:
line_graph graph = (line_graph)findViewById(R.id.lineGraph);
graph.setup(
//labels
new String[]{"heading1","heading2","heading3","heading4","heading5","heading6","heading7"},
//Values
new int[][]{new int[]{1,4,8,2,5,9,12},new int[]{2,5,2,8,5,2,6},new int[]{8,2,9,23,7,1,11}},
//Series Headings
new String[]{"Series 1", "Series 2", "Series 3"},
//Padding
20);
xml:
<line_graph
android:id="#+id/lineGraph"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
it looks like this:
And yes i do realize this could be made better and that it had poor exception handling. But its just an example.

Canvas getting wrong coordinates for finger drawing after pinch to zoom

I create canvas finger drawing app like line brush which is on https://play.google.com/store/apps/details?id=jp.naver.linebrush.android, I done pinch to zoom functionality but problem is after zoom in and zoom out, not drawing properly position on canvas area. For more understanding I share my View class for canvas drawing:
public class DrawingView extends View {
// Zooming Code 16-6-2015 4.12pm
private static final int INVALID_POINTER_ID = -1;
public Bitmap mMyChracter;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private int mActivePointerId = INVALID_POINTER_ID;
View currentView;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private float focusX;
private float focusY;
private float lastFocusX = -1;
private float lastFocusY = -1;
static final int IMG_WIDTH = 640;
static final int IMG_HEIGHT = 480;
static final int IMAGE_X_POS = 560;
static final int IMAGE_Y_POS = 20;
float sy;
float sx;
public static Context context;
// -------------------------------------
// ...................................
/*private final Bitmap bitmap;
private final int width;
private final int height;*/
private Matrix transform = new Matrix();
private Vector2D position = new Vector2D();
private float scale = 1;
private float angle = 0;
private TouchManager touchManager = new TouchManager(2);
private boolean isInitialized = false;
// Debug helpers to draw lines between the two touch points
private Vector2D vca = null;
private Vector2D vcb = null;
private Vector2D vpa = null;
private Vector2D vpb = null;
int mWidth;
int mHeight;
// ...............................
private final Paint mDefaultPaint;
private Paint mFillPaint;
float x, y;
private Canvas mLayerCanvas = new Canvas();
private Bitmap mLayerBitmap;
private Stack<DrawOp> mDrawOps = new Stack<>();
private Stack<DrawOp> mUndoOps = new Stack<>();
private SparseArray<DrawOp> mCurrentOps = new SparseArray<>(0);
// For Drag and Pan zoom Code initialization
private static float MIN_ZOOM = 1f;
private static float MAX_ZOOM = 2f;
private float scaleFactor = 1.f;
private static ScaleGestureDetector detector;
boolean mFlagDrawing;
private final Matrix mMatrix = new Matrix();
int y_old=0,y_new=0;int zoomMode=0;
float pinch_dist_old=0,pinch_dist_new=0;
int zoomControllerScale=1;//new and old pinch distance to determine Zoom scale
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
// We can be in one of these 3 states
static final int NONE = 0;
static final int PAN = 1;
static final int ZOOM = 2;
int mode = NONE;
private static final String TAG = "DebugTag";
// New Code
private Bitmap imgBitmap = null;
private int containerWidth;
private int containerHeight;
Paint background;
//Matrices will be used to move and zoom image
// Matrix matrix = new Matrix();
// Matrix savedMatrix = new Matrix();
// PointF start = new PointF();
float currentScale;
float curX;
float curY;
//We can be in one of these 3 states
// static final int NONE = 0;
// static final int DRAG = 1;
// static final int ZOOM = 2;
// int mode = NONE;
//For animating stuff
float targetX;
float targetY;
float targetScale;
float targetScaleX;
float targetScaleY;
float scaleChange;
float targetRatio;
float transitionalRatio;
float easing = 0.2f;
boolean isAnimating = false;
float scaleDampingFactor = 0.5f;
//For pinch and zoom
// float oldDist = 1f;
// PointF mid = new PointF();
private Handler mHandler = new Handler();
float minScale;
float maxScale = 8.0f;
float wpRadius = 25.0f;
float wpInnerRadius = 20.0f;
float screenDensity;
private GestureDetector gestureDetector;
public static final int DEFAULT_SCALE_FIT_INSIDE = 0;
public static final int DEFAULT_SCALE_ORIGINAL = 1;
private int defaultScale;
private static final String EXTRA_EVENT_LIST = "event_list";
private static final String EXTRA_STATE = "instance_state";
private ArrayList<MotionEvent> eventList = new ArrayList<MotionEvent>(100);
public DrawingView(Context context) {
this(context, null, 0);
}
public DrawingView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// detector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public DrawingView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mDefaultPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mDefaultPaint.setStyle(Paint.Style.STROKE);
mDefaultPaint.setStrokeJoin(Paint.Join.ROUND);
mDefaultPaint.setStrokeCap(Paint.Cap.ROUND);
mDefaultPaint.setStrokeWidth(40);
mDefaultPaint.setColor(Color.GREEN);
/*mFillPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mFillPaint.setStyle(Paint.Style.STROKE);
mFillPaint.setStrokeJoin(Paint.Join.ROUND);
mFillPaint.setStrokeCap(Paint.Cap.ROUND);
mDefaultPaint.setStrokeWidth(40);
mFillPaint.setColor(Color.GREEN);*/
setFocusable(true);
setFocusableInTouchMode(true);
setBackgroundColor(Color.WHITE);
setLayerType(LAYER_TYPE_SOFTWARE, null);
setSaveEnabled(true);
// Code for Zoom start
// detector = new ScaleGestureDetector(getContext(), new ScaleListener());
// Code for Zoom finish
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
private static float getDegreesFromRadians(float angle) {
return (float)(angle * 180.0 / Math.PI);
}
// Single Touch Code
#Override
public boolean onTouchEvent(#NonNull MotionEvent event) {
vca = null;
vcb = null;
vpa = null;
vpb = null;
final int pointerCount = MotionEventCompat.getPointerCount(event);
switch (MotionEventCompat.getActionMasked(event)) {
// switch(event.getAction()){
// switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
// case MotionEventCompat.ACTION_POINTER_DOWN:
{
if (mFlagDrawing == true) {
/* final float xx = event.getX() / mScaleFactor;
final float yy = event.getY() / mScaleFactor;
mLastTouchX = xx;
mLastTouchY = yy;
mActivePointerId = event.getPointerId(0);*/
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
final int id = MotionEventCompat.getPointerId(event, p);
DrawOp current = new DrawOp(mDefaultPaint);
current.getPath().moveTo(event.getX(), event.getY());
mCurrentOps.put(id, current);
}
}
// mFlagZoom = true;
// }
}
break;
case MotionEvent.ACTION_MOVE: {
// for(int p = 0; p < pointerCount; p++){
if (mFlagDrawing == true) {
/* final int pointerIndex = event.findPointerIndex(mActivePointerId);
final float xx = event.getX(pointerIndex) / mScaleFactor;
final float yy = event.getY(pointerIndex) / mScaleFactor;
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = xx - mLastTouchX;
final float dy = yy - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
}
mLastTouchX = xx;
mLastTouchY = yy;*/
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
// current.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
final int id = MotionEventCompat.getPointerId(event, 0);
DrawOp current = mCurrentOps.get(id);
final int historySize = event.getHistorySize();
for (int h = 0; h < historySize; h++) {
x = event.getHistoricalX(h);
y = event.getHistoricalY(h);
current.getPath().lineTo(x, y);
}
x = MotionEventCompat.getX(event, 0);
y = MotionEventCompat.getY(event, 0);
current.getPath().lineTo(x, y);
// position.add(current.getPath());
// }
}
}
break;
case MotionEvent.ACTION_UP:
// case MotionEventCompat.ACTION_POINTER_UP:
// {
if (mFlagDrawing == true) {
// mActivePointerId = INVALID_POINTER_ID;
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
final int id = MotionEventCompat.getPointerId(event, p);
mDrawOps.push(mCurrentOps.get(id));
mCurrentOps.remove(id);
// }
updateLayer();
}
}
// }
break;
case MotionEvent.ACTION_CANCEL: {
if (mFlagDrawing == true) {
// mActivePointerId = INVALID_POINTER_ID;
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
mCurrentOps
.remove(MotionEventCompat.getPointerId(event, p));
}
}
// mFlagZoom = true;
// }
}
break;
/*case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = event.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = event.getX(newPointerIndex) / mScaleFactor;
mLastTouchY = event.getY(newPointerIndex) / mScaleFactor;
mActivePointerId = event.getPointerId(newPointerIndex);
}
break;
}*/
default:
return false;
}
invalidate();
return true;
}
#Override
protected void onSizeChanged(int w, int h, int oldW, int oldH) {
super.onSizeChanged(w, h, oldW, oldH);
/*mLayerBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mLayerCanvas.setBitmap(mLayerBitmap);*/
if(mLayerBitmap == null){
mLayerBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
}else{
Bitmap temporary = Bitmap.createScaledBitmap(mLayerBitmap, w, h, true);
mLayerBitmap = temporary;
}
mLayerCanvas = new Canvas(mLayerBitmap);
// mLayerCanvas.rotate(90);
/* matrix.setTranslate(1.5f,1.5f);
matrix.postRotate(90, 2.5f, 2.5f);*/
// updateLayer();
/* //Reset the width and height. Will draw bitmap and change
containerWidth = w;
containerHeight = h;
if(mLayerBitmap != null) {
int imgHeight = mLayerBitmap.getHeight();
int imgWidth = mLayerBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
if(defaultScale == DrawingView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initY = (containerHeight - (int)imgHeight)/2;
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}*/
}
private void updateLayer() {
mLayerCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
for (DrawOp drawOp : mDrawOps) {
if (drawOp != null) {
drawOp.draw(mLayerCanvas);
}
}
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isInEditMode()) {
return;
}
// if(mFlagDrawing == true){
if (!isInitialized) {
int w = getWidth();
int h = getHeight();
position.set(w / 2, h / 2);
isInitialized = true;
}
mWidth = mLayerBitmap.getWidth();
mHeight = mLayerBitmap.getHeight();
// Code for Zoom start
/* canvas.save();
canvas.scale(mScaleFactor, mScaleFactor, focusX, focusY);
canvas.translate(mPosX, mPosY);*/
// canvas.scale(scaleFactor, scaleFactor);
/*canvas.scale(mScaleFactor, mScaleFactor, super.getWidth() * 0.5f,
super.getHeight() * 0.5f);*/
// Code for Zoom finish
// canvas.save();
transform.reset();
transform.postTranslate(-mWidth / 2.0f, -mHeight / 2.0f);
// transform.postRotate(getDegreesFromRadians(angle));
transform.postScale(scale, scale);
transform.postTranslate(position.getX(), position.getY());
canvas.drawBitmap(mLayerBitmap, transform, null);
// }
// else if(mFlagDrawing == false){
// canvas.drawBitmap(mLayerBitmap, 0, 0, null);
for (int i = 0; i < mCurrentOps.size(); i++) {
DrawOp current = mCurrentOps.valueAt(i);
if (current != null) {
current.draw(canvas);
}
}
// }
// Code for Zoom
// canvas.restore();
}
public void operationClear() {
mDrawOps.clear();
mUndoOps.clear();
mCurrentOps.clear();
updateLayer();
}
public void operationUndo() {
if (mDrawOps.size() > 0) {
mUndoOps.push(mDrawOps.pop());
updateLayer();
}
}
public void operationRedo() {
if (mUndoOps.size() > 0) {
mDrawOps.push(mUndoOps.pop());
updateLayer();
}
}
public void setPaintStrokeWidth(float widthPx) {
mDefaultPaint.setStrokeWidth(widthPx);
}
public void setPaintOpacity(int percent) {
int alphaValue = (int) Math.round(percent * (255.0 / 100.0));
mDefaultPaint.setColor(combineAlpha(mDefaultPaint.getColor(),
alphaValue));
}
public void setPaintColor(String color) {
mDefaultPaint.setColor(combineAlpha(Color.parseColor(color), mDefaultPaint.getAlpha()));
}
public void setPaintColor(int color) {
mDefaultPaint.setColor(combineAlpha(color, mDefaultPaint.getAlpha()));
}
public void setPaintMaskFilter(MaskFilter filter) {
mDefaultPaint.setMaskFilter(filter);
}
public void setPaintShader(BitmapShader shader) {
mDefaultPaint.setShader(shader);
}
public void setPaintColorFilter(ColorFilter colorFilter) {
mDefaultPaint.setColorFilter(colorFilter);
}
private static int combineAlpha(int color, int alpha) {
return (color & 0x00FFFFFF) | ((alpha & 0xFF) << 24);
}
private static class DrawOp {
private float x,y;
private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
private final Path mPath = new Path();
public DrawOp(Paint paint) {
reset(paint);
}
/*public void add(Vector2D moveDelta) {
// TODO Auto-generated method stub
this.x += moveDelta.getX();
this.y += moveDelta.getY();
}*/
void reset(Paint paint) {
mPath.reset();
update(paint);
}
void update(Paint paint) {
mPaint.set(paint);
}
void draw(Canvas canvas) {
canvas.drawPath(mPath, mPaint);
}
public Path getPath() {
return mPath;
}
/* public DrawOp add(DrawOp value) {
this.x += value.getX();
this.y += value.getY();
return this;
}*/
/*public float getX() {
return x;
}
public float getY() {
return y;
}*/
}
public void fillShapeColor(){
}
// Code for Zoom
/* private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
scaleFactor *= detector.getScaleFactor();
scaleFactor = Math.max(MIN_ZOOM, Math.min(scaleFactor, MAX_ZOOM));
invalidate();
return true;
}
}*/
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// float x = detector.getFocusX();
// float y = detector.getFocusY();
lastFocusX = -1;
lastFocusY = -1;
return true;
}
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
focusX = detector.getFocusX();
focusY = detector.getFocusY();
if (lastFocusX == -1)
lastFocusX = focusX;
if (lastFocusY == -1)
lastFocusY = focusY;
mPosX += (focusX - lastFocusX);
mPosY += (focusY - lastFocusY);
Log.v("Hi Zoom", "Factor:" + mScaleFactor);
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.5f, Math.min(mScaleFactor, 2.0f));
lastFocusX = focusX;
lastFocusY = focusY;
invalidate();
return true;
}
}
/* #Override
public Parcelable onSaveInstanceState()
{
System.out.println("save instance");
Bundle bundle = new Bundle();
bundle.putParcelable(EXTRA_STATE, super.onSaveInstanceState());
bundle.putParcelableArrayList(EXTRA_EVENT_LIST, eventList);
return bundle;
}
#Override
public void onRestoreInstanceState(Parcelable state)
{
if (state instanceof Bundle)
{
Bundle bundle = (Bundle) state;
super.onRestoreInstanceState(bundle.getParcelable(EXTRA_STATE));
eventList = bundle.getParcelableArrayList(EXTRA_EVENT_LIST);
if (eventList == null) {
eventList = new ArrayList<MotionEvent>(100);
}
for (MotionEvent event : eventList) {
// performTouchEvent(event);
}
return;
}
super.onRestoreInstanceState(state);
}*/
public void setDrawingFlag(boolean flag) {
// System.out.println("Before Set mFlag " + mFlagDrawing);
this.mFlagDrawing = flag;
// System.out.println("After Set mFlag " + mFlagDrawing);
}
public void moveCanvas(float x, float y) {
float dx = x - mLastTouchX;
float dy = y - mLastTouchY;
// Adjust for zoom factor. Otherwise, the user's finger moving 10 pixels
// at 200% zoom causes the image to slide 20 pixels instead of perfectly
// following the user's touch
dx /= (mScaleFactor * 2);
dy /= (mScaleFactor * 2);
mPosX += dx;
mPosY += dy;
// Log.v(TAG, "moving by " + dx + "," + dy + " mScaleFactor: " +
// mScaleFactor);
}
}
I found mistake and correct it by my self. Below is my code.
public void resetZoom() {
mPanX = mPanY = 0;
final Matrix m = new Matrix();
m.postScale(1f / DENSITY, 1f / DENSITY);
setZoom(m);
invalidate();
}
public void setZoomPosNoInval(float x, float y) {
mPanX = x;
mPanY = y;
}
public void setZoomPos(float x, float y) {
setZoomPosNoInval(x, y);
invalidate();
}
public void setZoomPosNoInval(float[] pos) {
setZoomPosNoInval(pos[0], pos[1]);
}
public void setZoomPos(float[] pos) {
setZoomPosNoInval(pos);
invalidate();
}
public float[] getZoomPos(float[] pos) {
if (pos == null)
pos = new float[2];
pos[0] = mPanX;
pos[1] = mPanY;
return pos;
}
public float getZoomPosX() {
return mPanX;
}
public float getZoomPosY() {
return mPanY;
}
public Matrix getZoom() {
return mZoomMatrix;
}
public Matrix getZoomInv() {
return mZoomMatrixInv;
}
public void setZoom(Matrix m) {
mZoomMatrix.set(m);
mZoomMatrix.invert(mZoomMatrixInv);
}

View scratch game to have the hide image

I want to do a game, a scratch game (mPaint1.setXfermode(new PorterDuffXfermode(Mode.CLEAR)); ) with 3 independants cases center on the screen. How to do that?
http://img822.imageshack.us/img822/868/35861879.png
Only one case on the screen display. When theses 3 cases are cleared then the score display in function of displayed images. Thank you.
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageView image = new ImageView(this);
image.setImageResource(R.drawable.ic_launcher);
CaseView caseOne=new CaseView(this, R.drawable.ic_launcher, 0);
//TableLayout table = (TableLayout)findViewById(R.id.matable);
TableRow tablerow = (TableRow)findViewById(R.id.marow);
//table.setLayoutParams(tableParams);
tablerow.addView(caseOne);
}
public class CaseView extends View {
private static final float MINP = 1f;
private static final float MAXP = 1f;
private Bitmap mBitmap1, _scratch = null;
private Canvas mCanvas1;
private Canvas mCanvas2, mCanvas3;
private Path mPath1;
private Paint mBitmapPaint1;
private Paint mPaint1;
private int IdImage;
private int positionTop = 0;
private String colorGold = "#E29F2B";
private boolean firstTime = false;
// private Bitmap image;
// private Paint paint;
boolean isErase;
public CaseView(Context ctx, AttributeSet attrs) {
super(ctx, attrs);
}
public CaseView(Context c, int resId, int positionTop) {
super(c);
this.positionTop = positionTop;
firstTime = true;
mPaint1 = new Paint();
mPaint1.setAntiAlias(true);
mPaint1.setDither(true);
mPaint1.setColor(Color.TRANSPARENT);
mPaint1.setStyle(Paint.Style.STROKE);
mPaint1.setStrokeWidth(60);
// create a square
mBitmap1 = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
for (int i = 0; i < 100; i++) {
for (int j = 0; j < 100; j++) {
mBitmap1.setPixel(i, j, Color.parseColor(colorGold));
}
}
mCanvas1 = new Canvas(mBitmap1);
mPath1 = new Path();
mBitmapPaint1 = new Paint(Paint.DITHER_FLAG);
// mBitmapPaint3 = new Paint(Paint.DITHER_FLAG);
IdImage = resId;
if (_scratch == null) {
_scratch = BitmapFactory.decodeResource(getResources(), IdImage);
}
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
// Log.v("", "onDraw");
canvas.drawColor(Color.WHITE);
// logo
canvas.drawBitmap(_scratch, 0, positionTop, null);
// canvas.drawBitmap(mBitmap1, null, new Rect(0,0,100,100),
// mBitmapPaint1);
canvas.drawBitmap(mBitmap1, 0, positionTop, mBitmapPaint1);
canvas.drawBitmap(_scratch, 0, 400, null);
canvas.drawBitmap(mBitmap2, 0, 400, mBitmapPaint2);
// mBitmap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
if ((mX < 100 && mX >= 0)
&& (mY < positionTop + 100 && mY >= positionTop)) {
// Log.v("onDraw", "x:" + mX + "/y:" + mY);
mPaint1.setMaskFilter(null);
mPath1.reset();
mPaint1.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
// mBitmap.setPixel((int) mY,(int) mX, Color.TRANSPARENT);
// mBitmap1.eraseColor(Color.TRANSPARENT);
mCanvas1.setBitmap(mBitmap1);
canvas.drawBitmap(mBitmap1, 0, positionTop, mBitmapPaint1);
invalidate();
} else {
mPaint1.setXfermode(null);
}
super.onDraw(canvas);
int pixelColor = mBitmap1.getPixel(50, 50);
int red = Color.red(pixelColor);
int green = Color.green(pixelColor);
Log.v("red", "red:" + red + " /green:" + green);
// invalidate();
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath1.reset();
mPath1.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath1.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mPath2.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath1.lineTo(mX, mY);
mPath2.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas1.drawPath(mPath1, mPaint1);
// kill this so we don't double draw
mPath1.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
Log.v("onTouchEvent", "x:" + x + "/y:" + y);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if ((mX < 100 && mX >= 0)
&& (mY < positionTop + 100 && mY >= positionTop)) {
mPath1.reset();
mPaint1.setMaskFilter(null);
mPaint1.setStrokeWidth(90);
mPaint1.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
// mCanvas1.draw(x, y, 10, mPaint1);
isErase = true;
} else {
mPaint1.setXfermode(null);
isErase = false;
}
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
if (isErase) {
mCanvas1.drawCircle(x, y, 20, mPaint1);
}
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
if (isErase) {
mCanvas1.drawCircle(x, y, 20, mPaint1);
}
touch_up();
invalidate();
break;
}
return true;
}
}

How to implement touch smooth image eraser in android?

I have already seen fingurePaint.java from API demos. I want to implement touch smooth eraser to erase parts of the image by touch move in android.
fingurePaint told me to implement this
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
But this is not working to erase the image. It is working to erase something which is drawn by touch.
public class SandboxView extends View implements OnTouchListener {
public final Bitmap bitmap;
private final int width;
private final int height;
private Matrix transform = new Matrix();
private Vector2D position = new Vector2D();
private float scale = 1;
private float angle = 0;
public boolean isInitialized = false;
private TouchManager touchManager = new TouchManager(2);
final GestureDetector mGesDetect;
// Debug helpers to draw lines between the two touch points
private Vector2D vca = null;
private Vector2D vcb = null;
private Vector2D vpa = null;
private Vector2D vpb = null;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private Path mPath;
private Canvas mCanvas;
private Paint mPaint;
private Paint mBitmapPaint;
public SandboxView(Context context, Bitmap bitmap) {
super(context);
this.bitmap = bitmap;
this.width = bitmap.getWidth();
this.height = bitmap.getHeight();
this.mGesDetect = new GestureDetector(context, new DoubleTapGestureDetector());
setOnTouchListener(this);
}
private float getDegreesFromRadians(float angle) {
return (float)(angle * 360.0 / Math.PI);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (!isInitialized) {
Bitmap mBitmap = bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPaint = new Paint();
mPath = new Path();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
mPaint.setAlpha(0);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
mPaint.setAntiAlias(true);
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
int w = getWidth();
int h = getHeight();
position.set(w / 2, h / 2);
isInitialized = true;
}
if(isEraser==1){
canvas.drawColor(80000000);
canvas.drawBitmap(bitmap, transform, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
else{
Paint paint = new Paint();
transform.reset();
transform.postTranslate(-width / 2.0f, -height / 2.0f);
transform.postRotate(getDegreesFromRadians(angle));
transform.postScale(scale, scale);
transform.postTranslate(position.getX(), position.getY());
canvas.drawBitmap(bitmap, transform, paint);
try {
/*paint.setColor(0xFF007F00);
canvas.drawCircle(vca.getX(), vca.getY(), 64, paint);
paint.setColor(0xFF7F0000);
canvas.drawCircle(vcb.getX(), vcb.getY(), 64, paint);
paint.setColor(0xFFFF0000);
canvas.drawLine(vpa.getX(), vpa.getY(), vpb.getX(), vpb.getY(), paint);
paint.setColor(0xFF00FF00);
canvas.drawLine(vca.getX(), vca.getY(), vcb.getX(), vcb.getY(), paint);*/
}
catch(NullPointerException e) {
// Just being lazy here...
}
}
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
}
#Override
public boolean onTouch(View v, MotionEvent event) {
if(isEraser ==1){
float x = event.getX();
float y = event.getY();
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
else{
vca = null;
vcb = null;
vpa = null;
vpb = null;
mGesDetect.onTouchEvent(event);
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
return true;
}
}
class DoubleTapGestureDetector extends GestureDetector.SimpleOnGestureListener {
#Override
public boolean onDoubleTap(MotionEvent e) {
colorseekbar.setVisibility(View.INVISIBLE);
opacityseekbar.setVisibility(View.INVISIBLE);
return true;
}
}
}
So please help me to erase the parts of image by using touch move.
Thanks in advance.
First Declar your paint with all property in your constructor.
Write this code in your onDraw() method
#Override
protected void onDraw(Canvas canvas)
{
System.out.println("come in on draw......");
canvas.drawColor(Color.TRANSPARENT);
canvas.drawBitmap(mBitmap, 0, 0, mPaint);
if(eraser==true)
mPaint.setColor(Color.TRANSPARENT):
else
mPaint.setColor(Color.RED):
canvas.drawPath(mPath, mPaint);
super.dispatchDraw(canvas);
}
second solution:
call below method in your touch_move() method
mBitmap.setPixel(x, y, Color.TRANSPARENT); This method will change your bitmap you have to pass only X,Y & COLOR
public void changeBitmap(int x, int y, Bitmap mBitmap)
{
Bitmap tempBitmap = Bitmap.createBitmap(mBitmap); //Edited code
tempBitmap.setPixel(x, y, Color.TRANSPARENT);
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
changeBitmap(x, y, your_bitmap)
}
}
Isn't it better to invert this case ? Just paint on your image with background color and after all when saving, merge those layers if needed.
Define a temporary canvas and bitmap then draw your path or line, circle, image anything on touch events and then pass this temporary bitmap to canvas in onDraw your work will done properly, and also if you want to do erasing then do your erasing on that temporary canvas.
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
TemporaryBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_4444);
TemporaryCanvas = new Canvas(TemporaryBitmap);
}
TemporaryCanvas.drawColor(0, PorterDuff.Mode.clear);
public void onDraw(Canvas canv){
canv.drawBitmap(TemporaryBitmap, matrix, paint);

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